There's a lot packed in to the Gigabyte 970A-UD3 for its £85 price point. Six full speed SATA 6Gb/s hard drive connectors is a good start, and so are the two front-panel USB 3.0 headers (there are two around the back as well).
It really doesn't feel like a 'value' board at all. In fact, the only thing that's really missing is Crossfire and SLI support. There's just one PCIe x16 slot for graphics cards, but so long as you aren't planning a dual card rig there seems to be little reason to upgrade to a more expensive AMD 990X board right now anyway.
Funnily enough, though, one of the best features is the set of augmented power USB ports round the back. If you've recently picked up an Apple iPad 2 or an Android tablet such as the BlackBerry PlayBook, you may have noticed that standard USB slots don't provide enough juice to charge their batteries. Some motherboard manufacturers throw in some overvolting software to try to get around that, but two of the rear ports here appear to have proper pins for non-standard charging.
Other than that, the best distinction Gigabyte has – other than the quality of its underlying components – is that it's one of the best value boards for Socket AM3+ so far, and a full-size ATX one, at that.
The Gigabyte 970A-UD3 is a smartly laid out board with some excellent extras such as super powered USB ports, a back up Bios and Bulldozer support for a very reasonable price.
For current Phenoms, there's not really enough to distinguish it over older 8-series boards that cost less. By the time Bulldozer actually arrives, it may not be the best value AM3+ option around.
Right now, the Gigabyte 970A-UD3 is the best value Bulldozer option. By the time the CPU arrives, however, that will likely have changed.
The tedious but true conclusion about any 970, 990X or 990FX board right now, though, is that until we know whether or not Bulldozer is any good, it's an odd time to decide on a future AMD platform for your next system. Come back in a couple of months, maybe.